Method and means for measuring current distribution



June 2, 1925. A

C. F. WAGNER METHOD AND MEANS FOR MEASURING CURRENT DISTRIBUTION Filed Jan. 14.. 1921 Fig.

R O T.. mE W8 l@ r M C WITNESSES: fyi/,vwl

Way/1er TTO'RNEYl CHARLES VJU'NER, GF El 'carin-ii, Assistme 'ro Winsen'No- HoUsn signora-re a ranrnrnernarne- Corneau r, oonronaloit or" rENNsYr'J- VANIA.;

VIETHOI) ANI)y fEANS GUvRET DISTRIBUTION.

Application filed January 14, 1921.

i0 @ZZ w/of/t t may concern.' I

Be it known 1Lhat l, friiiann l?. illaennr., a citizen ot the United States, and a resident ct Pittsburgh, in the county et Allegheny and State of Pennsylvania, have invented a n 'iv and `usefull improvement in ltlcthods and Means for li/leasurine Current. Distribution, of which the following is a speciii# cation. f

Mw invention relates to electrical testing ticuiarly to metheds of, and means t in and

determining current distri` ation. has-bars.

@ne (inject. et my invention is to provide a compaiifely simple method or deter mining certain operating characteristics oliV hns-bar or other conductor, from which de* ninatien other characteristics may v v l' sa my copian ,i ledl Sept. 2e, 1920, is disclosed means ttor overcoming the unequal distribution or' cin-rent in bus-bars.

lilly present inventionl relates to a simple and eieeti'f'e method Yfor determining certain data i; r use in connection -with the design of the device set forth in the aboveinentioned patent- A vice or ineans for lfacilitati'ngl the application o'ltlie method.

ln practicing my invention, l' provide a.

method for so indicatingcharacteristic differences between certain filament-ary portions'o-f, or Zones in, a single conductor as to facilitate thel compilation of data by which the condnctor may, in accordance with the disclosure of the above mentioned patent application, be constructed economically andfoperated effectively.

tion of filament'ary exploring conductors,

application L'lerial No.v

s application and to a cle-- Serial No. 437,329.

utilized' -in= the method: oi: my invention, op'-N eratively connected thereto;

Fig. 2 is a diagram otvolt'age vectors-l 'that are proportioned to theV val-uesY and? phase-angle relations oli current in dillerentV tilanientary elements of" thevbus-bar..

Fig 3 is a side elevational view ofy aportion of an insulating plate or holder, enrbodying my invention, for facilitating, the application oi' thc method.

Fig. i isa cross-sectional vView of the'y de# vice shown in Fig. 3.

Figs.- and 6 are diagrammatic views ot arrangements of conductors and devices fory measuring the vector sum of the I. R.l drops in the bas-bar and, y

Fig@ is-a diagrammatic View' of a modilied form of the system shown in Fig. l.

Referring tol Figs. land 2, spaced, fila@ menta'ry, insulated, exploring conductors l and 2,A of substantially equal length, are placed in side engagement, throughout-theirv lengths, againstthe side ol, and parallel to, a bus-bar 3' and electrically connected, at the ends 9 and l() thereor", to the bus-bar.l The insulating covering ot' the conductors l and 2 'is preferably very thin, such asl a coating of enamel, so thatthe conductors may lie as close as practicable to the busbars. rllhis arrangement provides, in effect, noninductive shunts'between the 'conductors l and 2 and adjacent elements m' and a, respectively, in the lbusbar and indicated, in cross section, as rectangles and, longitudinally, by dotted lines. Another exploringv conductor l is connected to the bar 3 adjacent to the opposite ends ot the conduetors 1 and 2. Y v

By connecting a volt meter across end portions 5 and 6 of the exploring conductors-- l and ll, respectively,a voltage that ijs-pro# portional to the resistance drop iI1-theelement 'in Will be indicated; Similarly., a if'eltage proportional to theresist-ance drop in the element n may be indicated, by placing the voltineter betweenI theendpjortion 6 of the conductor land an end portion 7 oi'f the :conductor 2. The latter voltage is equal to the vector sinn ot the resistance g drop in element m andthe induced voltage Figure l' of the accompanying. drawings isa broken perspective view o-fa portion of a bus-bari With a diagrammatic representa-V caused byv theluxbetween the elements m and n. rllheretore, to determine the phasef relation of voltages in the elements Wt and--E n, it is only necessary to measure the'voltage"v in n, I. R. drop in m and induced voltage in loop nr-n, found as above described, may be resolved to form a vector triangle, as 1ndicated in Fig. 2, from which the phase re# lations of the I. R. drops in the elements m and fn` may be determined and from these, by simple calculation, the phase relations and magnitudes of current densities in elements m and n. Y

By moving the conductors 1 and 2 to various positions on the bus-bar 3, or by prol viding a greatel number of similar conduc tors, the current distribution in magnitude and phase may be determined for the entire bus-bar.

' As shown in Figs. 3 and 4, a simple device for facilitating the vabove described method comprises an insulating plate 11 having a plurality ofiilalnentary exploring conduc tors 12 vdisposed along, or enlbedded in, one

lside surface 13 thereof, that are adapted to be placed against the'bar 3. The plate 11 has a thickened edge or shoulder portion 14 by which it may be conveniently positioned on thebar and upon which a clip spring 15, for pressing the conductors 12 into close engagement with the bar, is mounted, as by screws 16. Y

As shown in Fig. 5, a plurality of theexploring conductors 12 may be employed in conjunction with a plurality Vof' transform ers 17. Fach vconductor 12 is connected to one side of the primary winding 18 of one of the transformers 17 there being one transformer Vfor each conductor 12, and the opposite'side of each primary winding is con- 'nected to a common terminal connector 19,

corresponding to the conductor 4- of Fig, 1. Secondary windings 20 are connected in series with each other and with a kvoltmeter 21. This construction provides a convenient arrangement for electrically isolating the respective pairs of exploringl conductors, between which a measurement is being taken,

and for obtainingV the vector sum of their` respective I. B. drops.

A modified form of the system illustrated in Fig. 5, is shown in Fig. 6, in which a voltmeter is connected between an exploring conductor 22, extending diagonally along one side of the bus-bar 3, and the conductorV 4. This arrangement, while permit-ting an indication of the sum of the LAR. drops in the various elements of the bar, does not iso- Y tors.

late the voltmeter from the bar, as in the above described form.

A modified form of the system illustrated in Fig. 1, is shown in Fig. 7, in which one of the exploring conductors 1 and 2 may be longer than the other. While the system of Fig. 1 is to be preferred, the system of Fig. 7 may function similarly with a correction, in the calculations, for the difference in length of the exploring conductors 1 and 2.

lVhile I have shown and described my novel method and means for determining current distribution in conductors, it is to be understood that various changes, both as to 1. The method of determining currentV- distribution characteristics of a. main conductor which consists melectrically connect'- ing a plurality of auxiliary conductors to y the main conductor, in placingportions ofV the auxiliary conductors in adjacentv insu-V lated relation to the main conductor and indicating the eli'ects caused by energization of the main conductor between the auxiliary conductors.

2. The method of determining character istics of aV main conductor which consists in electrically connecting al plurality of elongated auxiliary conductors to the main conductor, in placing portions of the auxiliary conductors in insulated side-surface relation` to the main conductor while the latter isvelectrically energizedand indicating the effects between the auxiliary conductors.

3. The method of determining characteristics of a main conductor which consists in electrically connecting a plurality of ila-V mentary conductors to the main conductor,

in placing portions of the auxiliary conductors in adjacent insulated relation'to the' main conductor in conformity to the current stream lines of the latter and indicating the effect caused by energization of the main conductor between the filamentary conduc- 4. The method of determining characteristics of a main conductor which consists in electrically connecting a plurality of {ila- Inentary conductors to the main conductor, in placing portions of the auxiliary conduc-V tors in insulated side-surface relation to the main conductor in conformity ,tothe current stream lines of the latter and indicating the lel to the latter and indicating the effects caused between the iilamentary conductors by energization of the main conductors.

6. rl`he method ot' determining characteristics ot' a main conductor which consists in electrically connecting an auxiliary conductor to the main conductor, in electrically connecting an elongated auxiliary conductor to the main conductor and extending the same along a surface ot the main conductor in insulated relation thereto and indicating the effects caused by energization of the main conductor between the auxiliary conductors.

7. The method of determining characteristics oi a main conductor subject to a Tpredetermined applied potential which consists in electrically connecting auxiliary testing-conductor means thereto, in placing portions of said means adjacent to the main conductor in insulated relation thereto and indicating the effects caused by diti'erences in induced potential between ditl'erent parts ot the main conductor.

8. Means for determining current-distribution characteristics of a main conductor comprising a plurality ot exploring conductors tor electrical connection thereto and having portions for positioning adjacent to the main conductor in insulated relation thereto and indicating means i'or operative connection to said exploring conductors.

9. In a device 'for determining characteristics oi a main conductor, the combination with indicating means, of a supporting structure, a plurality of spaced lilamentary conductors supported on said structure for electrical connection to the mainconductor and having insulated portions for position along the surface of the main conductor, and means for operatively connecting the tilamentary conductors to the indicating means.

10, In a device `for determining characteristics or' a main conductor, the combination with indicating means, of a supporting structure, a plurality of spaced lilamentary conductors supported on said structure, means for mounting said structure on the main conductor with the tilamentary conductors electrically connected thereto but having portions insulated therefrom, and means oroperatively connecting the filamentary conductors to the indicating means.

il. In a device-tor determining current distribution in a bus-bar, the combination with indica-ting means, of an insulating supporting plate, a plurality of spaced lilamentary conductors, disposed along a side surface of the plate, means for mounting the plate on the bar and pressing the filamentary conductors against the same in contact therewith at certain points and insulated theretrom at other points, and terminal means for operatively connecting the lilamentary conductors to the indicating means.

l2. Means for determining current distribution characteristics @t a main conductor comprising a plurality of insulated exploring conductors electrically connected to the main conductor and disposed in predeterminedposition adjacent to the main conductor, an indicating device and means peratively connected between the exploring conductor and the indicating device.

18. Means ior determining current distribution characteristics of a main conductor comprising a plurality of local exploring circuits responsive to voltage dierences in diherent parts of the main conductor-and means for indicating the vector sum of all or said voltage dierences.

14. Means for determining current distribution characteristics of a main conductor comprising a plurality of local exploring circuits responsive to voltage differences in different parts of the main conductor, neans for indicating the vector sum of all ot said voltage differences and means for operatively connecting and insulating said indicating means with respect to said explorv ing circuits.

In testimony whereof, I have hereunto subscribed my name this th day of January 1921.

VCHARLES F. WAGNER. 

